Looking to make your MetroMax iQ™ shelving unit even more strong and versatile? Look no further than the 18" x 48" MetroMax iQ™ Storage Level Frame (M4F1848) from Metro. This four-sided frame will fit any 48-inch by 18-inch MetroMax Q® or MetroMax i™ shelving unit and is required for installing many of Metro’s drop-in accessories, including many of their drying racks and wire baskets. However, it can also be used to contain large or bulky objects stored on the shelving unit. Made from a polyurethane polymer that is remarkably strong and corrosion resistant, this storage level frame can also be used to add strength and rigidity to a shelving unit with fewer shelves or those that may not ordinarily support a lot on their own.